関連する実験動画
Updated: Jun 20, 2026
06:01
EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1
Published on: November 26, 2014
鉄 (III) コーロール複合体の顕著な軸の可動性
Crisjoe A Joseph1, Peter C Ford
1Department of Chemistry and Biochemistry, University of California-Santa Barbara, Santa Barbara, CA 93106-9510, USA.
Journal of the American Chemical Society
|May 5, 2005
まとめ
鉄 (III) コロラート複合体のフラッシュ光分解により,酸化窒素 (NO) が放出され,複合体は急速に再構成される. 電子に富んだコロラートリガンドとトリプレット鉄 (III) 状態はNOの再結合を加速し,弱いルイス塩基相互作用を示している.
科学分野:
- 無機化学 無機化学とは
- フォトケミストリー フォトケミストリー
- 協調化化学について
背景:
- コロレートリガンドは,強力な電子提供特性で知られているマクロサイクルリガンドです.
- コロラートリガンドを含む鉄 (III) 複合体は,潜在的三重基底状態を含むユニークな電子構成を示します.
- 酸化窒素 (NO) の金属中心への結合は,様々な化学的,生物学的プロセスにおいて極めて重要です.
研究 の 目的:
- 鉄 (III) ニトロシルコロラート複合物からの酸化窒素 (NO) の光活性性を調査する.
- フラッシュ光分解の後に鉄の中心にNOが再結合する運動を決定する.
- コロラートリガンドの電子特性の影響を解明するために,ルイスはNO結合ダイナミクスをベースにしています.
主な方法:
- フラッシュ光分解は,鉄 (III) ニトロシルコロラート複合物からNOのラビライゼーションを誘導するために使用されました.
- 時間解像度スペクトロスコピーは,鉄の中心へのNOの急速な再結合を監視するために使用されました.
- 速度定数と均衡定数を決定するために,ルイス塩基 (溶剤とピリジン) の濃度を変化させ,運動学的研究を行った.
主要な成果:
- 鉄 (((III)) ニトロシルコロラートのフラッシュ光分解により,迅速なNOの放出に続いて,迅速な再結合が起こりました.
- NO再結合 (kNO) の第2次率定数は,電子提供のコロラートリガンドとトリプレット鉄 (III) 状態に起因する,鉄性ポルフィリン類に匹敵する,例外的に高かった.
- ピリジンなどの柔らかいルイス基からの影響は最小で,軸性リンガンド結合は著しく弱まり,金属中心のルイス基への afinity が低いことを示しました.
結論:
- 強く電子を寄付するコロラートリガンドとトリプレート鉄 (III) の構成は,金属中心の軸性リガンドへの親和性を劇的に低下させる.
- この弱いルイス塩基相互作用は,配合溶剤の存在下でも,非常に速いNO再結合運動を促進します.
- この研究は,鉄コロラート複合体のユニークな電子特性と,その NO ダイナミクスの制御への影響を強調しています.
さらに関連する動画
12:44Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example
Published on: December 4, 2014
04:48Setup of Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry (CE-ICP-MS) for Quantification of Iron Redox Species (Fe(II), Fe(III))
Published on: May 4, 2020
関連する概念動画
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...